ارزیایی اثرات پخش سیلاب بر خصوصیات خاک و ویژگی‌های رویشی گونه‌های کنار، کهور و کرت در ایستگاه پخش‌سیلاب تنگستان، استان بوشهر

The soil and vegetative characteristics are so closely interrelated and interactive, in a region that, the study of one factor without considering the other one, is somehow worthless. This paper attempts to evaluate the effects of flood spreading on some soil properties and vegetative characteristics of: Nubk, Common mesquite and Gum arabic in mixed man-made forests. Three sections of the forest (300 hectares of the total flood spreading networks) were selected, in such a way, to be representative of the whole forest of region, at Tangestan flood spreading experimental station at Bushehr province. To evaluate the effects of flood spreading at elevation levels, each section of forest was divided into, two; upland and downland subdivisions. At each section six soil profiles (a total of eighteen profiles) were dug and the phisico-chemical properties were assessed. To evaluate the forest stand changes, basal area per hectare and percent crown canopy were estimated. A cluster sampling design, with 1600 square meters plots (40×40 meters), with an orientation of 4 plots around each profile was used. The field data and laboratory results were analyzed. The comparison of soil properties indicated that, sand percent, clay percent, silt percent, acidity, electrical conductivity, nitrogen, phosphorous and potassium amount have a significant difference among sections. Section one had the highest results and showed a better condition in relation to the others. The results indicated that flood water spreading had different effects on vegetative characteristics. The comparison of flood water spreading units indicated that percent crown canopy at downland subdivisions exhibits a more favorite conditions than upland. Mean basal area per hectares in section one is higher than the other sections.